Examples of Circular Motion

The motion of an object along a circular path while rotating on its axis is known as circular motion. When a particle moves along the circumference of a circular path, it is believed to execute a circular motion. One of the most critical aspects of circular motion is that the direction of motion changes continuously, unlike linear motion. 

Circular motion is of two types:

• Uniform Circular Motion
• Non-Uniform Circular Motion

The variable speed is the main difference between a uniform and non-uniform circular motion. In a uniform circular motion, an object moves along a circular path at a constant pace, and in a non-uniform circular motion, the object moves with a variable speed.

Let us understand circular motion in terms of angular variables.

Angular Variables

The following angular variables help determine various aspects of an object’s circular motion:

Angular Displacement

Angular displacement is a rotating particle’s turn of angle per unit of time. It is measured in radians and is represented by ∆θ.

Angular Velocity

In a circular motion, the particles’ rate of change in the angular displacement is termed angular velocity.

It is illustrated by:

ω = dӨdt

It is measured in rad/s. Besides, a circular motion particle also possesses linear velocity and corresponding linear speed.

v= dsdt

v= dsdt; s is the displacement of the particle

Relation Between Angular Velocity and Linear Speed

In vector form,

v= ω x r 

Where r is the particle’s vector position measured from the circle’s centre.

v = rω

In a circular motion, the acceleration of a particle has two components :

• Tangential acceleration’ a’: Acceleration in the direction of the particle’s velocity.

at= dvdt

• Radial acceleration ‘ar’: Acceleration in the direction of the centre of the circle is known as radial acceleration. It possesses the ability to change the direction of the velocity of a circular motion particle.

ar= v2/r

Angular Acceleration

The rate of change of angular velocity of a rotating particle is known as the angular acceleration. The unit of measurement is rad/s2 and is denoted by α.

• α = dw/dt = d2Ө/dt2

Depending on the particle’s nature of acceleration, the circular motion can be classified as uniform or non-uniform. For example, if a particle moves along the circular path with constant speed, the circular motion is called uniform circular motion. 

In a circular motion, the velocity vector constantly changes its direction at each point. Thus, the radial component of acceleration remains non-zero at all times. 

The tangential component of a circular motion takes up either a positive or negative value for non-uniform circular motion and a value of zero for uniform circular motion.

In a circular motion, the particle’s acceleration is directed towards the centre and is denoted by v2r. 

From Newton’s Second Law of Motion

Fcen = mv2r

Where m is the particle’s mass

Fcen is the centripetal force directed towards the centre of the circular path.

Examples of Circular Motion

Many objects in our daily life showcase circular motion. Some of the prominent examples of circular motion are listed below: 

Revolution of planets around the Sun

The most prominent example of the circular motion of the universe is the revolution of planets around the sun while rotating on their axis. They follow a fixed circular path that acts as the boundary, with the sun as the centre of this circular path.

Ferris wheel

One of the most viewed examples of circular motion is a giant wheel or Ferris wheel. It is the most talked-about amusement ride of a carnival or a fair. The cabins are attached to a rim. Thus, it is easy to witness the circular motion of the cabin through the movement of the giant wheel.

Satellites around the planets

Like the planets revolve around the sun, the artificial and natural satellites revolve around the earth in a circular motion. Thus, the satellites’ motion in a circular orbit around the globe is another example of circular motion in the real world.

Stone attached to a string

When a stone is attached to one end of the string and force is applied on the other end to swirl the stone in the air, the stone rises and follows a circular path. Thus, the swirling of stone using pressure on the string is another example of circular motion. The centripetal force acts on the stone and helps it maintain circulatory motion.

Conclusion

Circular motion is thus the motion of an object on a circular path. To determine the speed and acceleration of an object in a circular motion, one needs to use angular variables. The examples of circular motion depict how regularly it is used in all fields. It also helps us understand various everyday phenomena and the making of artificial wonders such as banked roads, vehicles and how the forces prevent the car from turning around on a curvy road. Thus, circular motion holds great importance in daily life.